Summer’s Coming – Let Mowerino Cut Your Grass

May 11, 2022 by Al Williams 22 Comments

In the Northern hemisphere, summer is about to hit us full bore. While we love the season, we do dislike lawn maintenance. Apparently, so does [salmec] who developed the Mowerino around an Arduino Mega 2560 board.

As you might expect, the robot uses sharp blades so, you probably want to be careful. There are sensors that allow the machine to self-navigate or you can control it via Bluetooth. This is one of those things that seems easy until you try to actually do it. Nylon trimmer string is probably safer, but it breaks and it is hard to keep it cutting. Blades are more robust but also riskier to things like rocks, fingers, and pets.

Moving around in the yard is also an issue. The Mowerino has some ordinary-looking caster wheels in the front. That might be a place for improvement since most yards are not friendly to that kind of wheel. The other thing we worried about is what happens to the grass clippings. Around here, a week of rain means your mower will choke on grass clippings. On the other hand, the Mowerino has a smaller blade so maybe that helps mitigate clipping clogging.

Overall, though, it looks like it might be a good place to start if you dream of robot groundskeepers patrolling your estate. Most of the mowers we see like this have big wheels. But, of course, not all of them.

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Arduino Brings USB Mouse To Homebrew Computer

October 18, 2021 by Tom Nardi 2 Comments

When building your own homebrew computer, everything is a challenge. Ultimately, that’s kind of the point. If you didn’t want to really get your hands dirty with the nuts and bolts of the thing, you wouldn’t have built it in the first place. For example, take the lengths to which [rehsd] was willing to go in order to support standard USB mice on their 6502 machine.

Code for mapping mouse movement to digital output.

The idea early on was to leverage existing Arduino libraries to connect with a standard USB mouse, specifically, the hardware would take the form of an Arduino Mega 2560 with a USB Host Shield. There was plenty of code and examples that showed how you could read the mouse position and clicks from the Arduino, but [rehsd] still had to figure out a way to get that information into the 6502.

In the end, [rehsd] connected one of the digital pins from the Arduino to an interrupt pin on the computer’s W65C22 versatile interface adapter (VIA). Then eleven more digital pins were connected to the computer, each one representing a state for the mouse and buttons, such as MOUSE_CLICK_RIGHT and MOUSE_LEFT_DOWN.

Admittedly, [rehsd] says the mouse action is far from perfect. But as you can see in the video after the break, it’s at least functional. While the code could likely be tightened up, there’s obviously some improvements to be made in terms of the electrical interface. The use of shift registers could reduce the number of wires between the Arduino and VIA, which would be a start. It’s also possible a chip like the CH375 could be used, taking the microcontroller out of the equation entirely.

From classic breadboard builds to some impressively practical portable machines, we’ve seen our fair share of 6502 computers over the years. Despite the incredible variation to be found in these homebrew systems, one thing is always the same: they’re built by some of the most passionate folks out there.

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RAMPS Rebuild Keeps Robox 3D Printer Out Of Junk Bin

August 7, 2021 by Matthew Carlson 11 Comments

A 3D printer is a wonderful invention, but it needs maintenance like every machine that runs for long hours. [Rob Ward] had a well-used Robox 3D printer that was in need of some repairs, but getting the necessary replacement parts shipped to Australia was cost-prohibitive. Rather than see a beloved printer be scrapped as e-waste, he decided to rebuild it using components that he could more easily source. Unfortunately the proprietary software and design of the Robox made this a bit difficult, so it was decided a brain transplant was the best path forward.

Step one was to deduce how the motors worked. A spare RAMPS 1.4 board and Arduino Mega2560 made short work of the limit switches and XYZ motors. This was largely accomplished by splicing into the PCBs themselves. The Bowden filament driver motor had a filament detector and an optical travel sensor that required a bit of extra tuning, but now the challenging task was next: extruding.

With a cheap CR10 hot end from an online auction house, [Rob] began modifying the filament feed to feed in a different direction than the Robox was designed for (the filament comes in at a 90-degree angle on the stock Robox). A fan was needed to cool the filament feed line. Initial results were mixed with lots of blockages and clogs in the filament. A better hot end and a machined aluminum bracket for a smoother path made more reliable prints.

The original bed heater was an excellent heater but it was a 240 VAC heater. Reluctant to having high voltages running through his hacked system, he switched them out for 12 VDC adhesive pads. A MOSFET and MOSFET buffer allowed the bed to reach a temperature workable for PLA. [Rob] upgraded to a GT2560 running Marlin 2.x.x.

With a reliable machine, [Rob] stepped back to admire his work. However, the conversion to the feed being perpendicular to the bed surface had reduced his overall build height. With some modeling in OpenSCAD and some clever use of a standard silicone sock, he had a solution that fed the wire into the back of the hot end, allowing to reclaim some of the build height.

It was a long twelves months of work but the write-up is a joy to read. He’s included STL and SCAD files for the replacement parts on the printer. If you’re interested in seeing more machines rebuilt, why not take a look at this knitting machine gifted with a new brain.

Zoom Out Of The Classroom With A Mushroom Button

February 4, 2021 by Kristina Panos 16 Comments

Considering the state of well, everything, we can’t tell you how glad we are to be out of school. That goes double for not being a teacher these days. [Elena] had some awesome light-up tactile buttons set aside for a killer Kerbal Space Program controller, but it’s funny how a pandemic will change your priorities. Instead, those buttons found a good home in this colorful and enticing Zoom control panel.

[Elena]’s ready pile of Arduinos yielded no Leonardos or Pro Micros, but that’s okay because there’s a handy bootloader out there that allows you to reprogram the USB interface chip of an Uno or a Mega and use it as a keyboard. After setting that up, it was mostly a matter of wiring all those latching and momentary buttons and LEDs to the Mega and making them look fantastic with a set of icons. (We all know the big red mushroom button is for aborting the call; so does it really need an icon?)

[Elena] was inspired by the Zoom call-terminating pull chain we saw a month or so ago as well as the pink control box that launched a thousand or so macro keyboards. Have you made your own sanity-saving solution for our times? Let us know!

Greeking Out With Arduinos

September 18, 2020 by Brian McEvoy 4 Comments

Learning a new language is hard work, but they say that the best way to learn something is to teach it. [Angeliki Beyko] is learning Greek, and what better way to teach than to build a vocabulary flash-card game from Arduinos, color screens, 1602 text screens, and arcade buttons? After the break, we have a video from the creator talking about how to play, the hardware she chose, and what to expect in the next version.

Pegboard holds most of the hardware except the color screens, which are finicky when it comes to their power source. The project is like someone raided our collective junk drawers and picked out the coolest bits to make a game. Around the perimeter are over one hundred NeoPixels to display the game progress and draw people like a midway game. Once invested, you select a category on the four colored arcade buttons by looking at the adjacent LCD screens’ titles. An onboard MP3 shield reads a pseudo-random Greek word and displays it on the top-right 1602 screen in English phonetics. After that, it is multiple choice with your options displaying in full-color on four TFT monitors. A correct choice awards you a point and moves to the next word, but any excuse to mash on arcade buttons is good enough for us.

[Angeliki] does something we see more often than before, she’s covering what she learned, struggled with, would do differently, and how she wants to improve. We think this is a vital sign that the hacker community is showcasing what we already knew; hackers love to share their knowledge and improve themselves.

Typing Greek with a modern keyboard will have you reaching for an alt-code table unless you make a shortcut keyboard, and if you learn Greek, maybe you can figure out what armor they wore to battle.

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Arduino Takes Control Of Dead Business Card Cutter

September 10, 2020 by Tom Nardi 13 Comments

It’s a common enough situation, that when an older piece of equipment dies, and nobody wants to spend the money to repair it. Why fix the old one, when the newer version with all the latest bells and whistles isn’t much more expensive? We all understand the decision from a business standpoint, but as hackers, it always feels a bit wrong.

Which is exactly why [tommycoolman] decided to rebuild the office’s recently deceased Duplo CC-330 heavy duty business card cutter. It sounds like nobody really knows what happened to the machine in the first place, but since the majority of the internals were cooked, some kind of power surge seems likely. Whatever the reason, almost none of the original electronics were reused. From the buttons on the front panel to the motor drivers, everything has been implemented from scratch.

An Arduino Mega 2560 clone is used to control four TB6600 stepper motor drivers, with a common OLED display module installed where the original display went. The keypad next to the screen has been replaced with 10 arcade-style buttons soldered to a scrap of perfboard, though in the end [tommycoolman] covers them with a very professional looking printed vinyl sheet. There’s also a 24 V power supply onboard, with the expected assortment of step up and step down converters necessary to feed the various electronics their intended voltages.

In the end, [tommycoolman] estimates it took about $200 and 30 hours of work to get the card cutter up and running again. The argument could be made that the value of his time needs to be factored into the repair bill as well, but even still, it sounds like a bargain to us; these machines have a four-figure price tag on them when new.

Stories like this one are important reminders of the all wondrous things you can find hiding in the trash. Any time a machine like this can be rescued from the junkyard, it’s an accomplishment worthy of praise in our book.

A Z80 Board With Very Few Parts

July 17, 2020 by Al Williams 25 Comments

The Z80 is one of those old CPUs that is both obtainable and easy to work with — at least in some versions. [Doctor Volt] put together what may be the simplest possible setups to get a working Z80 system. He has the processor, of course. But everything else — clock, memory, and power — are from an Arduino Mega 2560. You could argue that’s two chips, but the board actually has several chips on it. On the other hand, you could probably pull off the same stunt with a bare ATMega 2560.

We’ve seen this done before, but usually with a few more support chips. If you are a purist, [Doctor Volt] also has some Z80 and CP/M experiments where the Arduino only acts as a disk drive for the computer and there are only two support chips. There are three videos for both projects that you can see below.

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